KTET Paper 2: Science and Mathematics Test - 10 - KTET MCQ

Calculation:
Area of square room
= (10)² = 100 sq m = 100 × (100)² sq cm
= 100 × 100 × 100 sq cm
Now, area of tile
= (50)² = 50 × 50 sq cm
∴ Number of tiles needed
= Area of square room/Area of tile

Group teaching allows freedom for the students to interact freely and establish intimate contact with their teachers on the one hand and with peers on the other. A teacher intends to develop conflict resolution skills among his\her students. To realize this goal, the teacher can organize a variety of tasks.

• serves as an important tool to make learning meaningful by working together. In groups, students work collaboratively and involve in active learning. It provides an opportunity for the students to work together in an efficient way. 

Indicator: 

• The indicator is a substance that shows different colors in acidic and basic solution
• Beetroot juice is a pH indicator. 
• Baking soda solution is basic and beetroot is an indicator.
• Baking soda reacts with beetroot juice then, the secret message becomes visible. Hence, option 3 is correct.
• Whereas, common salt is an ionic compound and is neutral. So, it does not react with beetroot. 
• Glucose is a simple sugar. So, it does not react with beetroot. 
• Lemon juice is an olfactory indicator.
• Since beetroot is an indicator and turns red in an acidic medium whereas lemon contains citric acid which also turns red in an acidic medium. So, it does not react with beetroot. 

a = ((2013)² + 2013 + 2014)^1/2
= ((2013)² + 2013 + 2013 + 1)^1/2
= ((2013)² + 2 x 2013 x 1 + 12)^1/2
= ((2013 + 1)²)^1/2
= ((2014)²)^1/2 = 2014
Thus, option (4) is correct.

As sodium hydroxide is basic in nature, it will turn red litmus paper blue while it has no effect on blue litmus paper.

Given:
The HCF of 1683, 2244 and 5049 is x.
Concept used:
HCF - The greatest number which divides each of the two or more numbers
Calculation:
⇒ 1683 = 3 × 3 × 11 × 17
⇒ 2244 = 2 × 2 × 3 × 11 × 17
⇒ 5049 = 3 × 3 × 3 × 11 × 17
The HCF = (3 × 11 × 17)
⇒ 561
So,
⇒ x = 561
Now,
The sum of digits of x = (5 + 6 + 1)
⇒ 12
∴ The required sum of digits of x is 12.

Acid and Base

• X - Ammonium hydroxide, Y - Tartaric acid is the correct option. 
• Ammonium hydroxide is used as a window cleaner. 
• In grapes, tartaric acid is formed. 
• Potassium hydroxide is used for making soaps. 
• Oxalic acid is found in spinach. 

Echo is the acoustical phenomena in which there occurs a repetition of sound which is caused by the reflection of sound waves from an obstacle is known as echo

• For in order to occur echo the distance between the obstacle and sound source must be 17.2 m.

Age of father two years ago = 42 - 2 = 40 years
Age of son two years ago = 12 - 2 = 10 years
Ratio of ages of father and son = 40 : 10 = 4 : 1

Lindemann (1942) put forth ten percent law for the transfer of energy from one trophic level to the next.Plants utilise sun energy for primary production and can store only 10% of the utilised energy as net production available for the herbivores. When the plants are consumed by animals, about 10% of the energy in the food is fixed into animal flesh which is available for the next trophic level (carnivores). When a carnivore consumes that animal, only about 10% of energy is fixed in its flesh for the higher level.

A grass plant has fibrous roots and parallel venation.
Roots: All grasses have fibrous roots. These roots extend into the soil from base of the plant.
Leaves: Grass leaves have parallel venation. In this venation, veins run parallel to one another down the length of the leaf.

Given:
One bell rings every 6 minutes. Another bell rings every 8 minutes. The third bell rings every 9 minutes. 
Concept used:
LCM is the smallest common multiple of two or more numbers.
Calculation:
Now, the three bells will ring together after
⇒ LCM (6, 8, 9)
⇒ 23 × 32
⇒ 8 × 9
⇒ 72 minutes
∴ The three bells will ring together after 72 minutes.

The correct answer is i - d, ii - c, iii - b, iv - a

Plant Cell

• The cell wall in plant cells is made up of cellulose, a carbohydrate.
• The plant cell wall is an elaborate extracellular matrix that encloses each cell in a plant.
• It was the thick cell walls of cork, visible in a primitive microscope, that in 1663 enabled Robert Hooke to distinguish and name cells for the first time.
• The walls of neighboring plant cells, cemented together to form the intact plant, are generally thicker, stronger, and, most important of all, more rigid than the extracellular matrix produced by animal cells.

 Animal Cell

• Desmosomes are one of the stronger cell-to-cell adhesion types and are found in tissue that experience intense mechanical stress, such as cardiac muscle tissue, bladder tissue, gastrointestinal mucosa, and epithelia.
• Animal cells simply have a cell membrane, but no cell wall.

 Bacterial cell walls

• Bacterial cell walls are made of peptidoglycan also called as murein, which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids.

Fungal cell

• The cell wall is a characteristic structure of fungi and is composed mainly of glucans, chitin and glycoproteins.

• The Solar System's farthest planet known as Neptune is located eight planets from the Sun.
• It is the third-most massive, densest, and fourth-largest planet in the Solar System in terms of diameter.
• Its mass is 17 times that of the Earth.
• Being composed primarily of gases and liquids, it has no well-defined solid surface.
• The planet travels 30.1 astronomical units around the Sun on average during each of its 164.8-year cycles.
• It has the name of the sea god in Roman mythology.

For 3 years, P(1 + R/100)³ = 4,818 ...(i)
For next 3 years, 4,818(1 + R/100)³ = 7,227 ...(ii)
Using value of (1 + R/100)³ from eq. (i) in eq. (ii) and solving for P, we get
P = Rs. 3,212
Rs. = 3,212

In the gas phase, sulphur dioxide is oxidised by reaction with the hydroxyl radical via an intermolecular reaction:
SO₂ + OH. → HOSO₂·
which is followed by:
HOSO_2· + O₂ → HO₂· + SO₃
In the presence of water, sulphur trioxide (SO₃) is converted rapidly into sulphuric acid:
SO₃ (g) + H₂O (l) → H₂SO₄ (aq)
Nitrogen dioxide reacts with OH to form nitric acid:
NO₂ + OH· → HNO₃

Heredity is a term that refers to traits and features that are inherited from one's parents and ancestors. At birth, a person inherits 50% of each parent's genetic material (genes) that are passed along through the chromosomes found in the DNA. DNA (deoxyribonucleic acid) is the cell's genetic material, contained in chromosomes within the cell nucleus and mitochondria. A chromosome contains many genes.

Method of analysis and synthesis is applied for such problems in mathematics where ‘if-then’ type of logic is needed (If a triangle is isosceles, then prove that the measures of the angles opposite to the sides of equal length are equal). In such problems, some conditions (hypotheses) are given and under those conditions, some relationships have to be proved. In proving geometric relationships, and algebraic identities and in solving algebraic problems this method can be effectively used.
Synthetic Method: The word “synthetic’ is derived from the word ‘synthesis which means to combine. In this method, we combine several facts, perform cer­tain mathematical operations, and arrive at the solution. In this method, we start with the known data and connect it with the unknown part.
It is the process of putting together known bits of information to reach the point where unknown information becomes obvious and true. Thus in this method, we proceed from hypothesis to conclusion.
It is lead from:

• Known to Unknown
• Hypothesis to Conclusion
• Concrete to Abstract 
• Simple to Complex

The Analytical Method is a generic process combining the power of the Scientific Method with the use of a formal process to solve any type of problem. Analysis means breaking up into components.

• The use of the Analytical Method is critical to solving the sustainability problem because it appears that current processes are inadequate.
• They are intuitive, simple, and based on how activists approach everyday problems. 
• All scientifically based problem-solving approaches use the analytical method.
• It leads from conclusion to hypothesis.
• It proceeds from unknown to known. (opposite of synthetic method)

Hence, we can conclude that If and then kind of problem in mathematics the method of analysis and synthesis is applied.

We know that heat is produced when fuels are burnt. The amount of heat produced by burning or combustion of 1Kg of fuel is expressed in terms of calorific value. 

• It is also known as energy value or heat of combustion.
• It is measured in units of energy per amount of material, e.g. KJ/g or kJ/kg, where KJ is Kilo Joules.

Science learners need to know not only facts/concepts but also about the processes through which this knowledge is generated. Aspects of Nature of Science:

• Scientific knowledge is long-lasting yet tentative, that is Scientific knowledge is subject to change because we make new observations and tend to reinterpret the existing observations.
• Empirical evidence is used to refine and support ideas in Science
• Social and historical factors play a role in the construction of scientific knowledge
• Laws and theories play a central role in developing scientific knowledge, yet they have different functions
• Accurate record-keeping, peer review, and replication of experiments help to validate scientific ideas
• Science is a creative endeavor
• Science and Technology are not the same, but they have an impact on each other.

Hence, it can be concluded that the statement "Scientific knowledge is subject to change" means Scientific knowledge is long-lasting yet tentative.

The student thought that the negative sign will still be there and not get divided.

Biased opinion does not reflect the personality attribute of a person having scientific temper.

Difficulty index is a measure of the proportion of examinees who answered the item correctly; for this reason it is frequently called the p-value. Item discrimination is the degree to which students with high overall exam scores also got a particular item correct. These two indices are used in evaluation of questions in SAT.

School mathematics has to be in close relation to the social worlds of children where they are engaged in mathematical activities as a part of daily life.

• Chemical change occurs when their is a change in the chemical properties of a matter.
  • When 2 or more reactants react they produce a compund having a different chemical composition.
• When iron rusts it reacts with the oxygen and water in the air to form it's hydroxide.
  • the brown coloured rust is the hydroxide of iron (Fe(OH)₃).
  • Reaction is -  4Fe + 3O₂ + 6H₂O → 4Fe(OH)₃

The expository Approach is also known as the Transmission Approach. In this approach, the teacher is communicating maximum information to the students in a minimum of time. This approach helps the teacher to
cover the content to be taught to the students. This approach is widely used across all subjects and different levels of education by the teacher. The main proponent of this method is David P. Ausubel.
In the expository approach all the cues provided by the teacher while teaching, the deductive thinking wherein abstract content is differentiated by the teacher giving appropriate examples to the students. The teaching Learning process is totally controlled by the teacher.
Note that:

• In Discovery Approach some cues in the form of learning material are presented by the teacher to the students and using Inductive thinking, the students are expected to discover the concept or the generalization/rule. Therefore the teaching-learning process is partially controlled by the teacher and students are also involved to a great extent. 
• In an Inquiry approach, the students are given a problem or a discrepant event. The students will ask the teacher questions to collect the data and they through interaction find out a satisfactory solution to a given problem or explanation of the given discrepant event. In this approach, the teaching-learning process is totally controlled by the students.

Constructivist teaching is based on the belief that the teacher facilitates a process of learning in which students are encouraged to be responsible and autonomous.

In order to enhance the self-esteem of students, they should be allowed to take part in discussions and debates.

Being an acid, hydrochloric acid does not change the colour of turmeric indicator, as acids do not change the colour of turmeric indicator. Also, phenolphthalein indicator would remain colourless in acids.